scholarly journals Study on a Quaternary Working Pair of CaCl2-LiNO3-KNO3/H2O for an Absorption Refrigeration Cycle

Entropy ◽  
2019 ◽  
Vol 21 (6) ◽  
pp. 546 ◽  
Author(s):  
Yiqun Li ◽  
Na Li ◽  
Chunhuan Luo ◽  
Qingquan Su
Keyword(s):  
Heat Capacity ◽  
Crystallization Temperature ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Specific Enthalpy ◽  
Refrigeration Cycle ◽  
Absorption Refrigeration ◽  
Evaporation Temperature ◽  
Corrosion Rates ◽  
Specific Entropy

When compared with LiBr/H2O, an absorption refrigeration cycle using CaCl2/H2O as the working pair needs a lower driving heat source temperature, that is, CaCl2/H2O has a better refrigeration characteristic. However, the crystallization temperature of CaCl2/H2O solution is too high and its absorption ability is not high enough to achieve an evaporation temperature of 5 °C or lower. CaCl2-LiNO3-KNO3(15.5:5:1)/H2O was proposed and its crystallization temperature, saturated vapor pressure, density, viscosity, specific heat capacity, specific entropy, and specific enthalpy were measured to retain the refrigeration characteristic of CaCl2/H2O and solve its problems. Under the same conditions, the generation temperature for an absorption refrigeration cycle with CaCl2-LiNO3-KNO3(15.5:5:1)/H2O was 7.0 °C lower than that with LiBr/H2O. Moreover, the cycle’s COP and exergy efficiency with CaCl2-LiNO3-KNO3(15.5:5:1)/H2O were approximately 0.04 and 0.06 higher than those with LiBr/H2O, respectively. The corrosion rates of carbon steel and copper for the proposed working pair were 14.31 μm∙y−1 and 2.04 μm∙y−1 at 80 °C and pH 9.7, respectively, which were low enough for engineering applications.

A theoretical and experimental study of a novel recompression absorption refrigeration cycle

2001 ◽  
Vol 215 (1) ◽  
pp. 75-87 ◽  
Author(s):  
I. W. Eames ◽  
S Wu
Keyword(s):  
Experimental Study ◽  
Theoretical Study ◽  
Lithium Bromide ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Absorption Refrigeration ◽  
Corrosion Rates ◽  
Steam Ejector ◽  
Single Effect ◽  
Absorption Cycle

This paper describes a novel vapour absorption refrigeration cycle which uses a steam ejector to enhance the concentration process of the cycle. The paper provides a complete description of the cycle and presents the results of a theoretical study before going on to describe and evaluate the outcomes of an experimental programme. The results of this investigation showed that with the addition of a steam ejector as described the coefficient of performance (COP) of the single-effect lithium bromide absorption cycle can be increased from about 0.7 to at least 1.0 without any increase in corrosion rates often associated with high temperature vapour generators used in conventional machines of this type.

scholarly journals Thermodynamic Performance of a Double-Effect Absorption Refrigeration Cycle Based on a Ternary Working Pair: Lithium Bromide + Ionic Liquids + Water

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4200 ◽  
Author(s):  
Yiqun Li ◽  
Na Li ◽  
Chunhuan Luo ◽  
Qingquan Su
Keyword(s):  
Least Squares Method ◽  
Operating Temperature ◽  
Double Effect ◽  
Coefficient Of Performance ◽  
Specific Enthalpy ◽  
Refrigeration Cycle ◽  
Absorption Refrigeration ◽  
Temperature Range ◽  
Thermodynamic Performance ◽  
Operating Temperature Range

For an absorption cycle, a ternary working pair LiBr–[BMIM]Cl(2.5:1)/H2O was proposed as a new working pair to replace LiBr/H2O. The thermodynamic properties including specific heat capacity, specific enthalpy, density, and viscosity were systematically measured and fitted by the least-squares method. The thermodynamic performance of a double-effect absorption refrigeration cycle based on LiBr–[BMIM]Cl(2.5:1)/H2O was investigated under different refrigeration temperatures from 5 °C to 12 °C. Results showed that the ternary working pair LiBr–[BMIM]Cl(2.5:1)/H2O had advantages in the operating temperature range and corrosivity. Compared with LiBr/H2O, the operating temperature range was 20 °C larger, and the corrosion rates of carbon steel and copper were reduced by more than 50% at 453.15 K. However, the double-effect absorption refrigeration cycle with LiBr–[BMIM]Cl(2.5:1)/H2O achieved a coefficient of performance (COPc) from 1.09 to 1.46 and an exergetic coefficient of performance (ECOPc) from 0.244 to 0.238, which were smaller than those based on LiBr/H2O due to the higher generation temperature and larger flow ratio.

Preparation of Bi4Te3 highly oriented nanopillars array film with enhanced electrical properties

2018 ◽  
Vol 33 (2) ◽  
pp. 115-120 ◽  
Author(s):  
Jing Wu ◽  
Jikang Jian ◽  
Shufang Wang ◽  
Shuang Guo ◽  
Renbo Lei ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electrical Transport ◽  
Thermal Evaporation ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Vacuum Thermal Evaporation ◽  
Evaporation Temperature ◽  
Thermoelectric Transport Properties ◽  
Thermal Evaporation Deposition ◽  
First Time

The Bi4Te3 films with well-ordered orientation and microstructure were successfully prepared on SiO2 substrate by a vacuum thermal evaporation deposition technique for the first time. We discussed the effects of evaporation temperature and substrate temperature on the phase and its well-ordered growth of Bi4Te3 films. The formation of Bi4Te3 phase is owing to the differences of the saturated vapor pressure. The thermoelectric transport properties of the Bi4Te3 films were investigated and the (00l)-oriented nanopillars array film has a better electrical transport performance, whose value of PF is 0.032 mWm−1 K−2 at 339 K, approaching twice that of the non-oriented ordinary film. The enhanced electrical properties of Bi4Te3 films could be achieved via the high-crystallinity well-controlled (00l)-oriented nanopillars array.

scholarly journals Effects of nanoparticles on hydraulic cavitation

2018 ◽  
Vol 240 ◽  
pp. 03004
Author(s):  
Min-rui Chen ◽  
Jin-yuan Qian ◽  
Zan Wu ◽  
Chen Yang ◽  
Zhi-jiang Jin ◽  
...  
Keyword(s):  
Vapor Pressure ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Geometric Model ◽  
Pressure Ratio ◽  
Perforated Plate ◽  
Significant Parameter ◽  
Operation Conditions ◽  
Small Bubbles ◽  
Crucial Condition

When liquids flowing through a throttling element, such as a perforated plate, the velocity increases and the pressure decreases. If the pressure is below the saturated vapor pressure, the liquid will vaporize into small bubbles, which is called hydraulic cavitation. In fact, vaporization nucleus is another crucial condition for vaporizing. The nanoparticles contained in the nanofluids play a significant role in vaporization of liquids. In this paper, the effects of the nanoparticles on hydraulic cavitation are investigated. Firstly, a geometric model of a pipe channel equipped with a perforated plate is established. Then with different nanoparticle volume fractions and diameters, the nanofluids flowing through the channel is numerically simulated based on a validated numerical method. The operation conditions, such as the temperature and the pressure ratio of inlet to outlet, are the considered variables. As a significant parameter, cavitation numbers under different operation conditions are achieved to investigate the effects of nanoparticles on hydraulic cavitation. Meanwhile, the contours are extracted to research the distribution of bubbles for further investigation. This study is of interests for researchers working on hydraulic cavitation or nanofluids.

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